Various microbes live in the soil, and especially, aerobic microbes propagate under the condition that oxygen exists decompose and compose organic matters, coexist with the roots of plants to strengthen the roots so that the plants transpire.
As described above, the aerobic microbes, which are useful for cultivating crops, in the soil is decreased in activity and propagation by chemical fertilizers or agricultural pesticides, and it causes the use of more chemical fertilizers and agricultural pesticides in order to increase the yield of crops. Such use of chemical fertilizers and agricultural pesticides not only threatens consumers' health and causes secondary pollution of the soil and underground water but also has bad effect on the ecosystem and environment.
In order to solve the above problems, Korean Utility Model Registration No. 20-0464414 Y1 discloses an air and nutrition supplying apparatus for physically supplying fresh air into the soil. The air and nutrition supplying apparatus 10 buried in a plant habitat for inducing or supplying air and nutrition underground includes: an air and nutrition supplying unit 11 which is buried in the habitat to provide a path to infiltrate induced air and nutrition into the soil; an air supply inducing unit 12 which is disposed at one end of the air and nutrition supplying unit 11 exposed over the ground of the habitat and slantly converts the direction of the air horizontally flowing along the surface of the earth to induce the air to the air and nutrition supplying unit 11; and a discharging unit 14 which is disposed at the other end of the air and nutrition supplying unit 11 to discharge the induced air, nutrition and moisture directly under the discharging unit 14.
However, such an air and nutrition supplying apparatus 10 has several disadvantages in that it cannot smoothly supply air to the depth of the roots because a tube body is buried on the ground and in that air is not smoothly supplied if the inside of the tube body is filled with soil or sand because the apparatus indirectly communicates with the air through a supply tube. Therefore, Korean Patent Laid-open No. 10-2012-0020512 discloses an apparatus for promoting growth of crops having a separate supplying unit.
The apparatus for promoting growth of crops includes: a nutrient solution supplying unit 200 for supplying a nutrient solution (N) to the roots (R) of crops (C) by dripping; an air supplying unit 300 connected to the nutrient solution supplying unit for supplying air to the roots of the crops; a controller 400 connected to the nutrient solution and air supplying units for controlling the supply of the nutrient solution and the air, thereby supplying the nutrient solution and the air to the roots of the crops and supplying air to the entire roots of the crops by supplying the nutrient solution to the roots of the crops by dripping.
The apparatus for promoting growth of crops includes the air supplying unit using driving power, but because supplying members are mounted under the soil near stems of each of the crops in order to locally supply air by dripping, it is difficult to evenly supply air to the entire of the roots of the crops and there is a risk of breakage when a farmer lows or manages an agricultural machine on a farmland.